Locomotive boiler firebox



Nov. 11, 1941. H. FOX ETAL LOCOMOTIVE BOILER FIREBOX Filed April 26, 1939 Patented Nov. 11, 1941 UNITED STATES PATENT OFFICE LOCOMOTIVE BOILER FIREBOX Harry L. Fox, West Haven, Gonna, and Sigurd E. Ghristophersen, East Milton, Mass.

4 Claims.

This invention relates to improvements in locomotive boiler fireboxes and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

The locomotive boiler fireboxes with which the present invention is more especially concerned, are. those embodying therein one or more flat hollow water walls that; form a part of the circulating system of the. associated boiler. Fireboxes of the kind are known generally as si phon equipped fireboxes.

One of the objects of the'present invention is to increase the heating surface and the water steaming and circulating action of a siphon equipped locomotive boiler firebox without enlarging the size thereof and. thus avoid the undesirable reactions that would accompany the latter.

Another object of the invention is to provide means, in a siphon equipped locomotive boiler K firebox, whereby better circulation is established in the side water legsof the boilerand a better and more positive flooding of the" crown sheet is assured under low water conditions.

A. further object of. the invention. is to. provide, in a siphon equipped: locomotive boiler firebox, a structure which gives a truer reading; of the water in the gauge glass, insures cleaner surfaces of those sheetswith which the boiler water is in contact. and prolongs. the. period of usefulness of said sheets and the associated staybolts.

Again, it is an object. of the invention to pro vide, in a siphon equippedlocomotive boiler fire.- box, a structure which affords greater safety against crown sheet ruptures and at the same time. assists the siphon in resisting downward.

pressure stresses.

The above mentioned objects of the invention,.

as well as others, together with the several advantages thereof will more full appear as thev Fig. 3 is a transverse sectional view, on an enlarged scale, through one of a pluralit of side sheet circulator tubes embodied in. the firebox,

the plane of the section being indicated by the line 3-3' of Fig. 4.

Fig. 4 is a View in side elevation of oneof the circulator tubes employed in the improved fire box;

Fig. 5 is a view in side elevation of one of the finished circulator tubes when turned about its axis through about 90 from the position shown in Fig. 4.

Referring now in detail to that embodiment of the invention illustrated in the drawing, the firebox therein shown includes a crown sheet I0, inner side sheets H, inner back sheet I2, inner throat sheet I3, and the usual flue sheet, not shown herein.

i5 is the outer rear boiler sheet, IS the outer side sheets and 11 the outer throat sheet. The said sheets cooperate with the wrapper sheet of the boiler in forming the back water leg l8, side water legs l9--l9 and the front throat 20 respectively, all in communication with. the Water spaceof the boiler; 22 is the mud ring'that bottoms the side and back water legs as well as the front throat. The inner andouter back sheets l2 and i5 respectively are formed to provide a conventional fuel door opening 23 as appears in Fig. 1'. The before mentioned construction, is of course suitably staybolted in the manner found in locomotive boilers.

Within the firebox is located one or more water steaming and circulating elements in the nature of hollow water walls and which are known as thermic siphons and which water walls or thermic siphons, as here shown, are of the kind generally disclosed in the Nicholson Patent*1 ,337',720 of April 20, 1920. The'number of siphons employed in the firebox, is of course, dependent upon the size of the firebox.-

In the present instance, two of such siphons are arranged in and extend longitudinally'of the firebox in laterally spaced relation, with one siphon disposed upon each side of the longitudinal median plane of'the firebox. Each siphon isindicated as a whole bythe numeral 25.

Each siphon comprises a substantially triangularly shaped hollow body 25 and an inlet neck 21. The inlet neck is formed as a continuation of the bulged bottom 28 of the body. The front end 29 of the bodyis inclined downwardly and rearwardly to meet the neck by an inside corner 30. The rear end of the body, which is theshorter end, inclines downwardly and forwardly to merge into the associated end of the bottom of the body by an outside rounded corner or nose 3| as it is called. The bulged bottom and the inlet neck extends downwardly and forwardly toward the throat sheet l3 and in which said neck is fixedto'open into the front throat 20. The top end of the body 26 of each siphon is fixed in a longitudinal opening in the crown sheet so as to communicate with the water and steam space of the boiler above the crown sheet. The body portion 26 of each siphon being fiat, is braced by staybolts 32 against internal pressures.

The siphons, of course, increase the heating surfaces of the firebox and therefore increase the water circulating and steaming action of the boiler. To'further increase the heating surface as well as the steaming action of the boiler and the circulating action through the side water legs, there is provided in combination with the siphons the following construction: 33--33 indicates sets of side sheet circulators, with a set disposed between each siphon 25 and the adjacent side sheet H of the firebox, each set comprising a plurality of such circulators. The number of such circulators in each set is dependent upon the length of the siphon and this length in turn is dependent upon the size of the firebox. In the present instance, each set comprises three of such circulators.

Each circulator is herein shown as a straight length of seam-less tubing, having a cross sectional dimension that is greater in one direction than in a direction at a right angle thereto. In the present instance, each circulator has parallel fiat side walls 3-l-34 and rounded end walls 35 and the fiat sides are stayed together against internal pressures by the staybolts 36, (See Figs.

2 and 4.)

End portions of each tube, from which each circulator is made, are removed to provide oblique portions, considered in the direction of the greatest cross sectional dimension of the tube, thereby forming substantially parallel extremities 31-38 at opposite ends of the tube. This manner of producing a circulator tube is best shown in Figs. 3 and 4 wherein the portions removed from the ends of the tube are indicated by dotted lines.

In fitting such circulator tubes in the firebox, elongated openings 39 are formed in the outer sidewall of the body of each siphon at points well above the bottom bulged portion thereof.

These openings, which match with the oblique extremity at one end of a circulator tube, have their major dimensions arranged in a plane slightly inclined from the perpendicular so as to be substantially parallel with the inclination of the front end wall 29 of the siphon. For each opening 39 in the side wall of the siphon body, another and similar opening 40 is formed in the adjacent side sheet I l toward the bottom thereof and which opening matches the oblique extremity at the other end of the tube.

The tubes 33 are then positioned in the firebox with their end extremities positioned in the openings 39 and 40 respectively and are welded in position from inside of the firebox. Thus, the tubes are arranged in longitudinally spaced relation in the firebox and extend downwardly and outwardly from the point of connection to the side wall of the siphon body to the point of connection with the associated side sheet of the firebox, the greatest cross sectional dimension of the tubes being disposed in substantially the perpendicular plane. This presents a flat side of each circulator tube in that position for the best impingement or engagement of the products of the combustion on their way to the flues in the flue sheet.

In many instances, it may be desired in a siphon equipped firebox, to employ a fire arch therein. Such an arch may be composed of brick 4|, as indicated in dotted lines in Fig. I. Said brick rest at their ends in one instance against the bulged bottomof the siphons and the usual lugs on the side sheet and in another instance against the bulged bottoms of adjacent siphons. Such an arch will extend to a point rearward of the second circulator tube from the front and therefore certain bricks in the arch are cut away or otherwise formed to pass about portions of the front two circulator tubes in each set. It is not necessary, however, that an arch be employed in the firebox so far as the present invention is concerned and therefore the arch is indicated only generally in Fig. 1 and does not appear in Fig. 2.

In use, the circulator tubes produce a flow of water from the lower portion of the side water legs l9, into the top portion of the side wall of the body of each siphon above the bulged bottom thereof. It is apparent that the water and steam bubbles flowing up the tubes 33, enter the siphon body at an angle obliquely with respect to the opposite side wall of the siphon body with an action that easily deflects the water toward the outlet of the siphons for discharge into the water space above the crown sheet. With the tubes arranged so as to be slightly inclined forwardly toward the top end, the water leaving said tubes and entering the siphon body as mentioned, has a better forward directional flow as it gushes out of the top end of the siphon body. Therefore, the flow of the water in the siphons is directed upwardly and forwardly, so that the water readily enters the circulation route in the boiler with but a minimum of turbulence above the crown sheet. As the turbulence above the crown sheet is minimized, it is apparent that more accurate readings appear in the gauge glass. Furthermore, the circulation is increased in the side water legs and therefore the sheets thereof are kept in a cleaner condition, so that said sheets better resist the burning action and have a longer period of usefulness.

With the improved circulator tubes, it is an easy matter to cut the ends thereof to provide the proper length and that oblique line which will make said tubes fit a particular installation.

In describing our invention we have referred in detail to the form and arrangement of the parts involved, the same is to be considered only in the illustrative sense so that we do not wish to be limited thereto except as may be specifically pointed out in the appended claims.

We claim as our invention:

1. In combination with a locomotive boiler firebox including a crown sheet, side sheets, back sheet andfront sheet respectively, a flat hollow water wall in and extending longitudinally of the firebox and which, by thermal action, operates to cause a circulatory flow of water from the lower part of the boiler to the part above the crown sheet of the firebox, 'a side sheet circulator arranged transversely of the firebox between said water wall and the adjacent side sheet of the firebox and comprising a tube having a greater cross sectional dimension in one direction than in the other direction, said greatest dimension being disposed in a plane substantially transversely of the firebox, said circulator being secured at one end to one side of the water wall above the bottom thereof and extending downwardly and outwardly therefrom toward the side sheet of the firebox and in which it is operatively engaged to conduct water from said side water leg to said water wall.

2. In combination with a locomotive boiler firebox including a crown sheet, side sheets, back sheet and front sheet respectively, a fiat hollow water wall in and extending longitudinally of the firebox and which, by thermal action, operates to cause a circulatory fiow of water from the lower part of the boiler to the part above the crown sheet of the firebox, a side sheet circulator arranged transversely of the firebox between said water wall and the adjacent side sheet of the firebox and comprising a tube having a greater cross sectional dimension in one direction than in the other direction, said greatest dimension being disposed in a plane substantially transversely of the firebox, opposite ends of said circulator being formed to provide extremities arranged obliquely to the axis of the tube of which it is made, in the direction of the greatest cross sectional dimension thereof, said circulator being secured at one end to one side of the water wall and extending downwardly and outwardly therefrom toward the side sheet of the firebox and in which it is operatively engaged.

3. In combination with a locomotive boiler firebox including a crown sheet, side sheets, back sheet and front sheet respectively, a flat hollow and substantially vertical water wall disposed longitudinally in the firebox and which by thermal action operates to cause a circulatory fiow of water from the lower part of the boiler into that part thereof above the crown sheet, a conduit in the firebox in the form of a substantially flat tube with its major cross sectional dimension in a plane disposed substantially transversely of the firebox and having one end opening through one of the side sheets and extending upwardly, inwardly and forwardly therefrom and having its other end opening through the adjacent side of the water wall closer to its top than to its bottom and having such an inclination with respect to the water wall as will impart an upward and forward flow of the water in the general direction of the circulation route of the boiler to discharge the water with but a minimum of turbulence above the crown sheet.

4. In combination with a locomotive boiler firebox including a crown sheet, side sheets, back sheet and front sheet respectively, a fiat hollow and substantially vertical water wall disposed longitudinally in the firebox and which by thermal action operates to cause a circulatory flow of water from the lower part of the boiler into that part thereof above the crown sheet, a conduit in the firebox in the form of a substantially fiat tube with its major cross sectional dimension in a plane disposed substantially transversely of the firebox, both ends of said tube being formed to provide oblique but substantially parallel extremities having areas greater than the cross sectional area of said conduit, one of said extremities being fixed in an opening in one of the side sheets and extending upwardly, inwardly and forwardly therefrom, the other extremity of said tube being fixed in an opening through one side of the water wall closer to the top than to its bottom, said tube having such an inclination with respect to the water Wall as will impart an upward and forward flow to the water in the general direction of the circulation route of the boiler to discharge the water with but a minmum of turbulence above the crown sheet.

HARRY L. FOX. SIGURD E. CHRISTOPHERSE'N. 

